Lately, essential oils are trying to be used in food industry because of their biological activity. Essential oils (EOs) are natural compounds with a complex composition which have the potential to be used as antimicrobial agents in food system due to the fact that contain active principles present in plants, as many research have been already demonstrated. The objective of this study is to show that EOs have the potential to be used in food system like antifungal agents by inhibiting the growth of pathogenic moulds. The method used to evaluate the in vitro inhibition effect of essential oils is Agar diffusion disk method. A known amount of limonene, nonane, pinene and nerol was applied on 6 mm diameter disks and placed onto the agar surface where an inoculum with filamentous fungi from the genus Aspergillus was spread. After this, the plates were incubated for 9 days at 250C under aerobic conditions. By evaluating and measuring the colony diameter of the fungus colonised daily and comparing it with the diameter of the control it could be told that nerol and pinene have antifungal activity. Essential oils can be used in consumer goods as a natural alternative to conventional food preservatives because it can prevent the spoilage of the products and can increase the shelf life, this way ensuring the microbiological safety of food products.